There has been considerable uncertainty amongst botanists as to the best way of treating the genus Rhus, with some viewing it in a strict sense as comprising of around 35 species and electing to separate the other species into several distinct genera; whilst others prefer to view the genus in a looser sense being comprised of perhaps 250 species grouped into several subgenera. The genus is treated here in its strict sense, with many other species that have at times been included here being moved to the genera Cotinus, Searsia and Toxicodendron.

Common Name: Chinese Gall

General Information

Rhus chinensis is a deciduous shrub or small tree with an open, spreading crown' it usually grows from 2 - 12 metres tall. The bole can be 6 - 18cm in diameter[]. The plant has an extensive root system and spreads by means of suckers, often forming thickets[].
The tree has a range of uses including - producing an edible fruit; having medicinal properties; a source of tannins, dye plant and source of oil. It is gathered from the wild and mainly used locally. Galls produced as a result of insect activity on the plant are widely used medicinally in east Asia, especially in polyherbal preparations, and are often traded[]. A very ornamental plant, it is sometimes grown in gardens[].
Rhus chinensis has a very wide distribution, large population, is not currently experiencing any major threats and no significant future threats have been identified.The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

The genus Rhus is being treated in its strict sense here, so it excludes the many species with highly toxic and irritant sap (these are included in Toxicodendron). Although the two genera are very similar, it is relatively simple to distinguish which is which, the poisonous species (Toxicodendron) have axillary panicles and smooth fruits whilst non-poisonous species (Rhus) have compound terminal panicles and fruits covered with acid crimson hairs[, ].
Whilst the genus Rhus in this treatment is generally seen as having a non-toxic sap there are some suggestions that the sap of some species in the genus (including this one) can cause a skin rash in susceptible people.

Botanical References

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Range

E. Asia - China, Japan, Korea, India, Bhutan, Malaysia, Thailand, Laos, Cambodia, Vietnam, Indonesia.

Habitat

Lowland, hill, and mountain forests, forests along streams, thickets; at elevations from 100 - 2,800 metres[]. An understorey plant of primary and secondary forest and thickets at elevations from 900 - 1,200 metres in Indonesia[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	6.00 m
Pollinators	Bees
Self-fertile	No
Cultivation Status	Ornamental, Wild

Cultivation Details

Rhus chinensis is a plant of the warm temperate to tropical zones, found at elevations of 900 metres or more in Indonesia[]. It only has moderate cold-hardiness, tolerating short periods with temperatures down to around -8°c when it is fully dormant[]. Young growth in spring is more sensitive to cold, and can be damaged even by light frosts[].
Succeeds in a dry to moist, well-drained fertile soil in full sun to partial shade[, , ]. Plants are tolerant of urban pollution[].
The plants are susceptible to coral spot fungus[].
Plants have brittle branches and these can be broken off in strong winds[].
Plants in this genus are notably resistant to honey fungus[].
A dioecious species, both male and female forms must be grown if fruit and seed are required.

Edible Uses

Fruit - cooked[, , , ]. An acid flavour[]. It is also used medicinally[, ]. The fruit can be used as a salt or a rennet substitute[, ]. Individual fruits are quite small, with very little flesh, but they are produced in clusters and are easily harvested[].

Medicinal

Galls are produced on the leaves and petioles as a result of activity by the aphid Schlechtendalia chinensis and, to a lesser extent, by Schlechtendalia peitan. These galls are rich in tannins and are often used for their antisepic, astringent, haemostatic and styptic properties. Taken internally they are used to treat a range of conditions including chronic diarrhoea, haemorrhage, persistent cough with blood, spontaneous sweating, night sweats, bloody stool, urorrhoea and bloody sputum[, , ]. They are a frequent ingredient of polyherbal prescriptions for the treatment of various conditions, including diabetes mellitus[, , ].
Applied externally as a wash, powder etc, the galls are used to treat various injuries and conditions including burns, bleeding due to traumatic injuries, haemorrhoids and ulcers in the mouth[].

The leaves and the roots are depurative[]. They stimulate blood circulation[]. A decoction is used
in the treatment of haemoptysis, inflammations, laryngitis, snakebite, stomach-ache and traumatic fractures[, ].

The stem bark is astringent and anthelmintic[].
The root bark is cholagogue[].

The fruit is used in the treatment of colic[].

The seed is used in the treatment of coughs, dysentery, fever, jaundice, malaria and rheumatism[].

Some caution is advised in the use of the leaves and stems of this plant, see the notes above on toxicity.

Agroforestry Uses:

Rhus chinensis has been found growing in areas in China polluted by heavy metals, and has been shown to concentrate various of these metals in its tissues. It has a potential for use in phytoremediation projects, mainly as a means of locking them up and helping to restore the fertility of the soil[].

Other Uses

The leaves are rich in tannin. They can be collected as they fall in the autumn and used as a brown dye or as a mordant[].
Galls are produced on the leaves and petiols as a result of activity by the aphid Schlechtendalia chinensis, and to a lesser extent Schlechtendalia peitan. These are rich in tannins which are used in medicine, as a dyestuff and also for tanning various materials. The galls contain up to 77% tannin[]. The reports do not say if the galls are harvested before or after the insect has left the gall[].
A blue dye can be obtained from the galls[] that can also be used as an ink[].

An oil is extracted from the seeds[, ]. It attains a tallow-like consistency on standing and is used to make candles. These burn brilliantly, though they emit a pungent smoke[].

An extract of the plant is used as an ingredient in commercial cosmetic preparations as a skin conditioner[].
An extract of the galls produced on the plant is used as an ingredient in commercial cosmetic preparations as a skin conditioner[].
An extract of the leaves and stem is used as an ingredient in commercial cosmetic preparations as an antifoaming agent, antimicrobial, astringent, emollient and hair conditioner[].
An extract of the leaves and stems is used as an ingredient in commercial cosmetic preparations as a skin protector[].
An extract of the root is used as an ingredient in commercial cosmetic preparations as an emollient[].

The wood is soft and is not used[].

Propagation

Seed - best sown in a cold frame as soon as it is ripe. Pre-soak the seed for 24 hours in hot water (starting at a temperature of 80 - 90c and allowing it to cool) prior to sowing in order to leach out any germination inhibitors[]. This soak water can be drunk and has a delicious lemon-flavour. The stored seed also needs hot water treatment and can be sown in early spring in a cold frame[]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Cuttings of half-ripe wood, 10cm with a heel, mid summer in a frame[].
Root cuttings 4cm long taken in December and potted up vertically in a greenhouse. Good percentage[, ].
Suckers in late autumn to winter[].